Oxygen
Oxygen is one of the many elements of the periodic table. It is located in period 2 group 16. Its atomic number is 8 and its atomic mass is 15.9994 (rounded to 16), meaning that it has 8 protons and 8 neutrons in its nucleus and 8 outer electrons surrounding the nucleus. There are The chemical symbol for oxygen is O. Its melting point is 54.8 K, (-218.3°C or -361.12°F). Its boiling point is 90.2 K (-183°C or -297.4°F). In standard room temperature at its gaseous state, oxygen is 1.429g/cm3. Oxygen is a nonmetal, meaning that it doesn’t have any properties of metals.
In normal conditions, oxygen is in its diatomic form, 02 , an odorless, colorless gas. When liquefied, oxygen is a light blue liquid. Oxygen is most commonly found in water and air, and because of this, it is a very important and essential element. It also exists in many other places, such as the Earth’s crust and the human body! Without it, no living thing (humans, plants, and animals) could survive. It is the 3rd most abundant element in the universe. Nearly 1/5thof the Earth’s atmosphere is made up of oxygen, and about half the earth’s crust is oxygen. 2/3 the mass of a human body is composed of oxygen. Oxygen is also extremely reactive. It can form oxides with all elements except neon, argon, krypton, and helium.
The name “oxygen” is derived from Greek roots meaning “acid forming.” It was originally discovered in 1772 by Carl Willhelm Scheele. Two years later, another man by the name of Joseph Priestly discovered the same element and spread the news around before Scheele did, leading many people to think that Priestly discovered oxygen first.
Oxygen has many uses, some helpful, and some harmful. As stated before, oxygen supports life, and is a big part of the Earth’s crust, and the human body. It plays a part in the carbon-nitrogen cycle, the photosynthesis cycle, and the respiration cycle. It can be found in the bright red, yellow, and green of the Northern Lights, or the Aurora Borealis. Hospitals often prescribe oxygen for their patients to help them breathe. Scuba divers use oxygen tanks to breathe underwater. Oxygen used to be the atomic weight standard used to compare other elements until in 1961 when the International Union of Pure and Applied Chemistry changed the atomic weight standard to carbon 12 instead. However, oxygen can be harmful when it is in the form of ozone (O3), because it damages lungs when breathed in. Exposure to oxygen with higher pressures than normal (for example, scuba divers), can lead to convulsions. Large amounts of oxygen are used to make ammonia, methanol, and ethylene oxide.
Mimi Giang 13yrs - 8 grade . Mưa phố núi 's first daughter
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